The Rawlings® S100 batting helmet is built for protection. This is achieved by using a composite insert that provides additional durability in critical ball impact locations. The S100 also uses a multiple impact expanded polypropylene (EPP) liner for added protection. These two interior layers further reinforce the outer helmet shell and interior padding creating four independent layers of protection that make up the Advanced Impact Management System or AIMS™. The S100 uses a combination of Outlast® and Pro-Dri® material for superior comfort. Pro-Dri® is a moisture management material that also fights bacteria. Outlast® Thermocules™ continually absorb, store and release excess body heat to balance temperature and humidity buildup. Protection doesn't mean you have to sacrifice comfort.